The worldwide use of automobiles, trucks and other internal combustion engine vehicles is believed to cause significant environmental damage. In one estimate, 590 million passenger vehicles operating worldwide consume an average of 550 gallons of gasoline per year, resulting in a worldwide consumption of 324,500,000,000 gallons of gasoline per year. It is also estimated that each vehicle exhausts on a yearly basis an average of 80 pounds of smog-causing hydrocarbons, 606 pounds of carbon monoxide, 41 pounds of nitrogen oxide (which causes acid rain and contributes to smog) and 10,000 pounds of carbon dioxide (which is believed to cause global climate change).
Hybrid electric vehicles (HEV) use multiple distinct power sources to propel the vehicle, generally including a combustion engine power source (e.g. a gasoline, diesel or biofuel engine), as well as an on-board no-emission/exhaust or low-emission/exhaust “green” power source. Illustrative but not exhaustive examples include hybrid green sources, rechargeable electrical energy storage and drive systems, natural gas systems, hydrogen fuel cell systems, compressed air systems and solar energy systems, though others will be apparent to one skilled in the art. Although use of an on-board no-emission green energy source to propel the hybrid generally results in little or no direct harmful emissions or non-renewable fuel source use, hybrids must still generally use their combustion engine power sources as well in order to accomplish some trips, thus still resulting in the generation of vehicle exhaust and/or the consumption of non-renewable fuel resources.